Infrared sensors have been developed over the years for detecting infrared information emitted by natural scenes. Such sensors are particularly useful in navigation and military tactical applications.
The infrared scenes from which these sensors observe and extract information contain a wide variety of materials having emissivity and temperature variations which are spatially distributed to produce radiance contrast patterns. These patterns contain information necessary for contrast between natural figures and military targets and for navigation by map matching.
A major concern in the use of infrared sensors in such applications is the problem of infrared background radiation on the detector. Since the contrast of natural infrared scenes is relatively poor to begin with, control and reduction of background radiation and improvement of the signal to noise ratio is vital in such applications. Accordingly, an infrared sensor which minimizes background radiation and provides a good signal to noise ratio is needed for such applications.